1. Field of the Invention
The present invention relates to a processor for printing a requested print job via a recording medium or a network, and more particularly to a processor in which a function to execute a print job is extended.
2. Description of the Related Art
In general, if a printer is connected to a computer main body a user is using, when a text file is created, the contents of the file are stored after confirming the contents by looking at what is displayed on a screen of the computer main body or what is printed through the printer.
However, as a system, in which a plurality of users share a common printer for printing files they create, there is a print system in which a network is configured by UNIX, which is an operating system or OS that can deal with a multiple users and in which one or a plurality of printers are connected to the network, whereby a plurality of users perform printing on the printers via the network. With this system, the printers are not used exclusively by the specific users but the printers are configured so as to be used by all the users having accesses to the system.
In order to realize a system like this, a server device is connected to the network, and one or a plurality of printers are connected in turn to the server device.
When there are requests for printing made by the respective users, an lp print service program is activated and print data of the print requests from the respective users are printed in order.
In this print system, the print data stored in the medium or the print data requested for printing via the network is read and the print data so read is then outputted to the printer for printing. However, when the requested print data has been printed on the printer, the print server device is configured so as to automatically delete the print file stored in a print data storing unit.
Even when there occurs a jam or the like on the printer side, as long as the print file remains in the print data storing unit, it is possible to recover the print file. However, since the print file is deleted as soon as the printing of the file is completed, it is not possible to print the data of the same print file. To cope with this, in a case where the same print data is to be reprinted on the printer, another request for printing the same print data has to be made.
In addition, even in a case where the print data from the medium or the network is outputted directly from a print job reading unit to the printer, if there occurs a jam or a failure in printing a specific page on the printer side, it is not possible to perform re-printing without another request for printing for the same print data.
Furthermore, although it can be conceived that the print file is left at the print data storing unit without being automatically deleted, in order to deal with a tremendous number of requests for printing jobs, the capacity of the storing unit has to be gigantic. Moreover, the operator is required to perform an additional operation of deleting the print data which has been printed by confirming that the data has become unnecessary.
Additionally, in a case where a print job requested by the print server device is printed on the printer, the print file of the print job in question is stored in the print data storing unit, and the requested printing is performed after the print data is read in the lp print service unit. This causes a problem that it takes time since the print job arrives at the print server device before the requested printing is initiated on the printer.
As is described above, it can be conceived that the print data is outputted directly from the print job reading unit to the printer and, in this method, since the print data is outputted to the printer without being read in the storing unit on its way to the printer, the time required from the request to the printing can be reduced.
However, although even if this method can reduce the time, in the event that there occurs trouble on the printer side or that the same print data is to be re-printed, not only does the method require another request for printing but also an advantage inherent in the lp print service, that a multiple accesses from a plurality of users can be dealt with, is lost.
To cope with this, a problem must be solved that the time required from a request for printing to the completion of the requested printing is reduced while making effective use of the lp print service.
Additionally, in a print system constituted by a print server device and a printer, when a request for printing is made, the lp print service receives a print job and outputs print data after spooling the same data.
At this time, since the lp print service is designed to normally output requested print jobs in a sequential fashion, in a case where the printing sequence is to be changed, the printing sequence has to be changed by separately making use of the function of the lp print service.
The print jobs accepted by the lp print service have attribute values of priority and the lp print service is provided with a function to change the printing sequence by changing the priority in printing sequence by changing in turn the attribute values.
However, this function can be used for a single print job, and therefore, in a case where a plurality of print jobs are spooled, there are caused several problems.
Namely, the priority has to be changed for every print job each time. Additionally, this function is a function to determine the priority by numerical values, and since the numerical value has a range (with the UNIX, 0 to 39), in a case where the number of print jobs exceeding the range are stored, printing cannot be performed in an expected sequence. Furthermore, a plurality of print jobs are stored, since the stored print jobs are printed one by one end, if the priority is changed for each printing, printing may be performed in an erroneous sequence depending on changing timings.
In a case where print jobs accepted and spooled by the lp print service unit are to be printed in a sequence following a specific condition, the conventional technologies have not been able to provide effective means. Printing is performed in an erroneous sequence, which is attributed to the fact that a process in which the priority is changed and a process in which the lp print service unit outputs to a device control filter cannot be performed in synchronism with each other.
Due to this, once a specific condition is set, the print priority must be determined in accordance with the condition so determined and the print sequence must be automatically changed.
To this end, an object of the present invention is to increase the convenience of a print server device by making effective use of the function of an lp print service and further improving the function as the print server device.